CN1055062C - Method for synthesis of small granular NaY molecular sieve - Google Patents

Abstract

The present invention provides a method for synthesizing NaY molecular sieve with small granules. The method has the preparation processes that conventional guiding agents are prepared first, ethanol solvent is then added into the conventional guiding agents so as to concentrate the guiding agents, and improved guiding agents with high concentration are prepared after the conventional guiding agents are aged for 2 to 20 hours, wherein the light transmittance of the improved guiding agents is higher than 30%, and the molar composition is (10-30)Na2O: Al2O3: (10-21)SiO2: (100-400)H2O. When the improved guiding agents are used for the hydrothermal synthesis of NaY molecular sieves with different formulation, NaY molecular sieves whose granules are about 0.1 to 0.3 mu m are prepared.

Description

A kind of synthetic method of small granular NaY molecular sieve

The invention belongs to the synthetic technology of molecular sieve, particularly the method for synthetic small granular NaY molecular sieve.

The NaY molecular sieve is widely used in petroleum catalytic cracking and petrochemical industry, is compared with macrobead NaY molecular sieve by the cracking catalyst that small granular NaY molecular sieve makes, and heavy oil fluid catalytic cracking is had higher activity and selectivity preferably.

The synthetic method of common NaY molecular sieve is to prepare conventional directed agents earlier, then conventional directed agents is joined in the synthetic colloid, by the synthetic NaY molecular sieve of different prescription hydro-thermals.This synthetic method is raw materials used cheap, and crystallization time is short, and the particle of sintetics is bigger, generally between 0.3-1.0 μ m.U.S. Pat 3,516,786 disclose a kind of adding organic solvent (as methyl alcohol, ethanol, methyl-sulphoxide etc.) that passes through in total synthetic system, makes the method for small granular NaY type molecular sieve, and the shortcoming of this method is big and difficult recovery of consumption of organic solvent.

The purpose of this invention is to provide a kind of method of improving the synthetic small granular NaY molecular sieve of directed agents that adopts, this method consumption of organic solvent is little and be easy to reclaim.

The synthetic method of small granular NaY molecular sieve of the present invention is carried out as follows:

(1). prepare conventional directed agents,

(2). preparation improves directed agents: with concentration is the ethanol organic solvent of 80-100% (weight), the 50-400% of directed agents volume joins in the conventional directed agents routinely, mix stirring 0.5-2 hour down at 15-50 ℃, under 15-50 ℃, left standstill then aging 2-20 hour, system is divided into two-layer up and down, remove upper water-ethanolic soln and obtain the transparent improvement directed agents colloidal sol that lower floor's transmittance is 30-95%, its mole consists of (10-36) Na ₂O: Al ₂O ₃: (10-21) SiO ₂: (100-400) H ₂O,

(3). hydro-thermal is synthetic: the hydro-thermal of carrying out different ingredients according to the method for the synthetic NaY molecular sieve of conventional directed agents is synthetic, and the add-on of wherein improving directed agents is that 0.5-25% is (with total Al in the system ₂O ₃The mole number meter), make the small granular NaY molecular sieve product.

In the method for the invention, the hydro-thermal synthesis process of the preparation of conventional directed agents and different ingredients all can carry out with reference to prior art.Characteristics of the present invention are conventional directed agents to be improved and the directed agents that is improved with ethanol, again with improved directed agents hydrothermal synthesis method and the synthetic short grained NaY molecular sieve of prescription routinely.

In this method, the concentration of described adding alcohol solvent is 90-100% (weight), and add-on is the 100-400% of conventional directed agents volume.

Described mixing whipping temp is 25-45 ℃, and churning time is 0.5-1.0 hour.

Described lower floor solution is for improving directed agents, and its mole consists of (10-19) Na ₂O: Al ₂O ₃: (12-19) SiO ₂: (150-250) H ₂O.

Described improvement directed agents must leave standstill after ethanol dehydration aging 6-20 hour.

Described improvement directed agents its transmittance after wearing out is 70-95%.

The add-on of improving directed agents in hydro-thermal is synthetic is 1.0-20% (Al in system ₂O ₃Meter).

Water-ethanol mixing solutions among the present invention can be reused after dewatering.

Relatively to have long service life, storage period long for said improvement directed agents and conventional directed agents among the present invention, the characteristics of high temperature resistant (about 50 ℃).By this synthetic NaY of method institute sieve particle little (0.1-0.3 μ m), and be uniformly dispersed.

Accompanying drawing 1 is the transmission electron microscope photo of the embodiment of the invention 1, and its effective particle diameter is 0.12 μ m.

Accompanying drawing 2 is the transmission electron microscope photo of Comparative Examples, and its effective particle diameter is 0.45 μ m.

The following examples will the invention will be further described.

Embodiment one

The preparation of sodium aluminate solution: sodium hydroxide (chemical pure) is dissolved in the deionized water, evenly add aluminium hydroxide (analytical pure) then, stirred 5 hours at 120 ℃, treat to be mixed with different causticities than (Na according to test requirements document below the as clear as crystal postcooling to 60 of solution ℃ ₂O/Al ₂O ₃Mol ratio) sodium aluminate solution.

With 45 milliliters of sodium silicate solutions (modulus 3.48, proportion 1.262, SiO ₂Concentration 252.8 mg/ml, the water glass plant, Qingdao) at room temperature mixes stirring 1 hour with 26 milliliters high basicity sodium aluminate solutions (causticity than 11.35, proportion 1.3935, Al2O3 concentration 45.9 mg/ml), under 35 ℃, left standstill then aging 6 hours, and made mole and consist of 16.0Na ₂O: Al ₂O ₃: 16.3SiO ₂: 328H ₂O, transmittance are 5% conventional directed agents.

Get 71 milliliters of ethanol (analytical pure) and join in the conventional directed agents, stirring at room 1 hour left standstill aging 1 hour at 40 ℃ then, system layering, upper water-ethanolic soln is separated, and lower floor is that a kind of transmittance is 82% improvement directed agents, and its mole consists of: 11.9NaO ₂: Al ₂O ₃: 13.4SiO ₂: 163H ₂O.

According to mol ratio is 3.6Na ₂O: Al ₂O ₃: 9.8SiO ₂: 200H ₂The NaY hydro-thermal synthesizing formula of O improves directed agents, 114 milliliters of alum liquors (proportion 1.2625, Al with 532 milliliters ₂O ₃Concentration 87.0 mg/ml) and 140 milliliters of low alkali aluminium acid sodium solutions (proportion 1.2660, causticity is than 2.48, Al ₂O ₃Concentration 99.8 mg/ml) mix to stir 1 hour, be warming up to 97 ℃ then, crystallization 20 hours after filtration, washing, drying, obtains SiO ₂/ Al ₂O ₃Than being 5.0, the effective NaY zeolite product of particle diameter 0.12 μ m, analytical results sees Table 1.

Embodiment two

Except amount of alcohol added is (with a conventional directed agents volumetric flowmeter) 200%, other experimental procedure is with embodiment one, and the analytical results of product sees Table 1.

Embodiment three

Except amount of alcohol added is (with a conventional directed agents volumetric flowmeter) 50%, other experimental procedure is with embodiment one, and the analytical results of product sees Table 1.

Embodiment four

Except amount of alcohol added is (with a conventional directed agents volumetric flowmeter) 25%, other experimental procedure is with embodiment one, and the analytical results of product sees Table 1.

Embodiment five

Place (with conventional directed agents volumetric flowmeter) 84 hours except improving the directed agents room temperature, other experimental procedure is with embodiment one, and the analytical results of product sees Table 2.

Embodiment six

Place (with conventional directed agents volumetric flowmeter) 108 hours except improving the directed agents room temperature, other experimental procedure is with embodiment one, and the analytical results of product sees Table 2.

Embodiment seven

Place (with conventional directed agents volumetric flowmeter) 48 hours except improving the directed agents room temperature, other experimental procedure is with embodiment four, and the analytical results of product sees Table 2.

Comparative Examples

Except not adding ethanol to the technology of conventional directed agents, other experimental procedure is with embodiment one.The analytical results of product sees Table 1,2.

Table 1

Table 2

Data in the table:

1.X the optical diffraction method is measured degree of crystallinity, the lattice constant a of NaY molecular sieve _o, and structure SiO ₂/ Al ₂O ₃Ratio and lattice constant a _oThe pass be: ${\mathrm{SiO}}_2/A{l}_2{O}_3=\frac{25.858-a_o}{a_o-24.191}\×2$

2.N ₂The determination of adsorption method specific surface, micro pore volume, its China and foreign countries' specific surface adopts the T-Plot method, T span 0.6-0.8 nanometer, the pass of T and pressure P is:

T＝{13.9900/[0.0340-log(p/P0)]} ^1/2

Effective particle diameter d (μ m) and external surface area Sex (m ²/ g) relation: $d=\frac{6}{\mathrm{\ρ}.\mathrm{Sex}}$

Wherein ρ is theoretical pellet density: the 1.92g/cm of NaY molecular sieve ³

Claims (7)

1. the synthetic method of a small granular NaY molecular sieve is characterized in that carrying out as follows:

(1) prepare conventional directed agents,

(2) preparation improves directed agents: with weight concentration is the ethanol organic solvent of 80-100%, join in the conventional directed agents, its add-on is the 50-400% of directed agents volume, stirred 0.5-2 hour down at 15-50 ℃, after leaving standstill aging 2-20 hour under 10-50 ℃, system is divided into two-layer up and down, removes upper water-alcohol mixed solution then, making lower floor's transmittance is 30-95%, and mole consists of (10-36) Na ₂O: Al ₂O ₃(10-21) SiO ₂: (100-400) H ₂The improvement directed agents colloidal sol of O,

(3) hydro-thermal is synthetic: the hydro-thermal of carrying out different ingredients according to the method for the synthetic NaY molecular sieve of conventional directed agents is synthetic, and the add-on of wherein improving directed agents is total Al in the system ₂O ₃The 0.5-25% of mole number makes the small granular NaY molecular sieve product.

2. method according to claim 1, the weight concentration that it is characterized in that described alcohol solvent is 90-100%, add-on is the 100-400% of conventional directed agents volume.

3. method according to claim 1 is characterized in that described mixing whipping temp is 25-45 ℃, and churning time is 0.5-1.0 hour.

4. method according to claim 1 is characterized in that described lower floor solution for improving directed agents, and its mole consists of (10-19) Na ₂O: Al ₂O ₃: (12-19) SiO ₂: (150-250) H ₂O.

5. method according to claim 1 is characterized in that described improvement directed agents must leave standstill aging 6-20 hour after ethanol dehydration.

6. method according to claim 1 is characterized in that described improvement directed agents its transmittance after wearing out is 70-95%.

7. method according to claim 1, its spy is that the add-on of improvement directed agents in hydro-thermal is synthetic is total Al in the system ₂O ₃The 1.0-20% of mole number.

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